Apparatus and method for landing and setting slip assembly

ABSTRACT

Slip assemblies that can be used for gripping pipes and running tools for installing such slip assemblies are provided. In one embodiment, an apparatus includes a slip bowl assembly having a slip bowl and a plurality of slip segments movably affixed to the slip bowl for movement between a setting position and a running position. The apparatus also includes a running tool having an inner sleeve positioned within an outer sleeve. The outer sleeve holds the plurality of slip segments in the running position to facilitate installation of the slip bowl assembly and the inner sleeve is configured to move with respect to the outer sleeve so as to cause the plurality of slip segments to move from the running position to the setting position. Additional systems, devices, and methods are also disclosed.

BACKGROUND

This section is intended to introduce the reader to various aspects ofart that may be related to various aspects of the presently describedembodiments. This discussion is believed to be helpful in providing thereader with background information to facilitate a better understandingof the various aspects of the present embodiments. Accordingly, itshould be understood that these statements are to be read in this light,and not as admissions of prior art.

In order to meet consumer and industrial demand for natural resources,companies often invest significant amounts of time and money in findingand extracting oil, natural gas, and other subterranean resources fromthe earth. Particularly, once a desired subterranean resource such asoil or natural gas is discovered, drilling and production systems areoften employed to access and extract the resource. These systems may belocated onshore or offshore depending on the location of a desiredresource. Further, such systems generally include a wellhead assemblymounted on a well through which the resource is accessed or extracted.

Wellhead assemblies may include a wide variety of components, such ascasing heads, tubing heads, and devices for hanging tubular strings(e.g., casing) within the well. For example, casing strings of differentdiameters in the well can be suspended from respective casing hangersinstalled in a wellhead. In some applications, it may be desirable toalso hang a coiled tubing string in a well. Various clamping devices areused in many situations to engage a cylindrical body, such as a pipe orcasing, within a circumscribing structure. Slips are examples of suchclamping devices.

SUMMARY

Certain aspects of some embodiments disclosed herein are set forthbelow. It should be understood that these aspects are presented merelyto provide the reader with a brief summary of certain forms theinvention might take and that these aspects are not intended to limitthe scope of the invention. Indeed, the invention may encompass avariety of aspects that may not be set forth below.

Embodiments of the present disclosure generally relate to slipassemblies. In some embodiments, an apparatus includes a slip assemblyhaving slip segments and a running tool to facilitate installation ofthe slip assembly in a bore of a housing. The slip segments are receivedin a slip bowl in a manner that allows movement of the slip segmentsbetween a running position and a setting position. The slip segments areheld in the running position, such as with shear pins, duringinstallation of the slip assembly. In some instances, this allows theslip segments to be moved along a casing string and over a protrudingportion (e.g., a collar) of the casing string. Once positioned withinthe housing, the slip segments are moved to the setting position to gripthe casing string or some other member to be held by the slip segments.In certain embodiments, the running tool causes the slip segments toshear the shear pins and move from the running position to the settingposition.

Various refinements of the features noted above may exist in relation tovarious aspects of the present embodiments. Further features may also beincorporated in these various aspects as well. These refinements andadditional features may exist individually or in any combination. Forinstance, various features discussed below in relation to one or more ofthe illustrated embodiments may be incorporated into any of theabove-described aspects of the present disclosure alone or in anycombination. Again, the brief summary presented above is intended onlyto familiarize the reader with certain aspects and contexts of someembodiments without limitation to the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of certain embodimentswill become better understood when the following detailed description isread with reference to the accompanying drawings in which likecharacters represent like parts throughout the drawings, wherein:

FIG. 1 generally depicts various components, including one or moretubular strings and associated slips, that can be installed at a well inaccordance with an embodiment of the present disclosure;

FIG. 2 is an exploded section view of a slip bowl assembly and a runningtool in accordance with an embodiment of the present disclosure;

FIG. 3 is a cross-section of the slip bowl assembly and running tool ofFIG. 2, with slip segments of the slip bowl assembly shown in a runningposition and the slip bowl assembly landed in a wellhead body inaccordance with an embodiment of the present disclosure;

FIG. 4 is a cross-section of the slip bowl assembly and running tool ofFIG. 3, with the slip segments shown in a setting position in thewellhead body in accordance with an embodiment of the presentdisclosure;

FIG. 5 is a cross-section of the slip bowl assembly within the wellheadbody following removal of the running tool in accordance with anembodiment of the present disclosure; and

FIG. 6 is a flowchart representing a method of installing the slip bowlassembly in a wellhead in accordance with an embodiment of the presentdisclosure.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Specific embodiments of the present disclosure are described below. Inan effort to provide a concise description of these embodiments, allfeatures of an actual implementation may not be described in thespecification. It should be appreciated that in the development of anysuch actual implementation, as in any engineering or design project,numerous implementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which may vary from one implementation toanother. Moreover, it should be appreciated that such a developmenteffort might be complex and time-consuming, but would nevertheless be aroutine undertaking of design, fabrication, and manufacture for those ofordinary skill having the benefit of this disclosure.

When introducing elements of various embodiments, the articles “a,”“an,” “the,” and “said” are intended to mean that there are one or moreof the elements. The terms “comprising,” “including,” and “having” areintended to be inclusive and mean that there may be additional elementsother than the listed elements. Moreover, any use of “top,” “bottom,”“above,” “below,” other directional terms, and variations of these termsis made for convenience, but does not require any particular orientationof the components.

Turning now to the present figures, a system 10 is illustrated in FIG. 1in accordance with one embodiment. Notably, the system 10 can be aproduction system that facilitates extraction of a resource, such asoil, from a reservoir 12 through a well 14. Wellhead equipment 16 isinstalled on the well 14. As depicted, the wellhead equipment 16includes at least one casing head 18 and tubing head 20 (which may alsobe referred to as wellhead housings or spools), as well as slips 22. Butthe components of the wellhead equipment 16 can differ betweenapplications, and could include a variety of casing heads, tubing heads,spools, hangers, sealing assemblies, stuffing boxes, pumping tees, andpressure gauges, to name only a few possibilities. As depicted, thesystem 10 also includes a blowout preventer (BOP) 11 mounted above thewellhead equipment 16. Though a single BOP 11 could be used, it will beappreciated that a BOP stack having multiple BOPs 11 will be mountedabove the wellhead equipment 16 in some instances.

The slips 22 can be positioned on landing shoulders 24 within hollowwellhead bodies (e.g., within the tubing head 20 and casing head 18).These landing shoulders 24 can be integral parts of tubing head 20 andcasing head 18 or can be provided by other components, such as sealingassemblies or landing rings disposed in the tubing and casing heads.Slips 22 can grip a tubular string, such as a tubing string 26 or acasing string 28, to suspend the string within the well 14. The well 14can include a single casing string 28 or include multiple casing strings28 of different diameters.

Slips 22 may be provided in any suitable form, an example of which isdepicted in FIG. 2. This depicted embodiment includes a running tool 100and a slip bowl assembly 102. The running tool 100 includes a runningtool pipe 104 having at its lower end an inner sleeve 106 positionedwithin an outer sleeve 110. As presently shown, the inner sleeve 106 isthreaded to the running tool pipe 104, while the outer sleeve 110 of therunning tool 100 hangs from retention pins 108 (e.g., dowel pins)carried by the inner sleeve 106. More particularly, the retention pins108 extend radially outward from the inner sleeve 106 into travel slotsor grooves 109 on the interior surface of the outer sleeve 110. The pins108 and grooves 109 cooperate to allow the inner sleeve 106 to moveaxially with respect to the outer sleeve 110 while retaining the outersleeve 110 to the inner sleeve 106. The outer sleeve 110 also includesshear pins 112 for fastening slip segments 120 of the slip bowl assembly102 to the outer sleeve 110, and retainer screws or other fasteners 114for coupling the running tool 100 to the slip bowl assembly 102. Asdiscussed further below, the outer sleeve 110 holds (via the shear pins112) the slip segments 120 in a running position to facilitate runningof the slip bowl assembly 102 into a wellhead housing (or other body),and relative movement of the inner sleeve 106 with respect to the outersleeve 110 facilitates shearing of the shear pins 112 and setting of theslip segments 120.

The slip bowl assembly 102 depicted in FIG. 2 includes a slip bowl 116,which has a landing shoulder 119 configured to land the slip bowlassembly 102 against a mating landing shoulder (e.g., shoulder 24) of awellhead housing (e.g., casing head 18). In the presently depictedembodiment, the slip bowl 116 is annular in nature and has asubstantially conical inner surface 117.

A plurality of slip segments 120 are positioned circumferentially aboutthe slip bowl 116 with some clearance between adjacent slip segments120. Any number of slip segments 120 is contemplated, though in certainembodiments the number of slip segments 120 ranges from four to eight.Each slip segment 120 is movably affixed to, and retained in, the slipbowl 116 by a holding pin 122 extending from the slip segment 120through an elongated slot 124 in the slip bowl 116. The slip segments120 are carried in the interior of the slip bowl 116 and move (e.g., bydownward force or by gravity) along the conical inner surface 117,guided by the holding pins 122 in the elongated slots 124, from an upperretracted running position to a lower setting position. The slipsegments 120 include outer surfaces 115 that slide on the conical innersurface 117 of the slip bowl 116 (which biases the sliding slip segments120 inward into the setting position) and slip teeth 123 on interiorsurfaces of the slip segments 120 for gripping a pipe, a casing string,some other tubular string, or some other member to be held.

Retaining slots 118, such as keyhole slots, are provided in the topsurface of the slip bowl 116 for receiving the retainer screws 114 tocouple the running tool 100 to the slip bowl assembly 102. In oneembodiment, retaining slots 118 are configured such that coupling anduncoupling from retainer screws 114 extending axially from the outersleeve 110 can be accomplished by rotating the running tool 100 withrespect to the slip bowl assembly 102. More specifically, with retainingslots 118 provided as keyhole slots, the running tool 100 can be coupledto the slip bowl assembly 102 by inserting heads of the retainer screws114 through wider portions of the keyhole slots and then rotating therunning tool 100 and the slip bowl assembly 102 with respect to oneanother to move the retainer screws 114 into narrower portions of thekeyhole slots. In such an embodiment, the running tool 100 and the slipbowl assembly 102 could be uncoupled in the reverse manner—that is, byrotating the components to align the heads of the retainer screws 114with the wider portions of the keyhole slots and then pulling therunning tool 100 and the slip bowl assembly 102 apart.

Running of the slip bowl assembly 102 over a casing string 126 and intoa wellhead housing 130 (e.g., casing head 18) is generally depicted inFIG. 3. The casing string 126 includes casing joints connected togetherwith casing collars 128. The increased diameter of the casing string 126at a casing collar 128 can interfere with installation of certain slipassemblies within a wellhead. With the running tool 100 and slip bowlassembly 102 coupled together as shown in FIG. 3, however, the shearpins 112 fasten the slip segments 120 to the outer sleeve 110 so as tohold the slip segments 120 in a retracted running position, in which thediameter of the region generally circumscribed by the retracted slipsegments 120 is greater than the outer diameter of the casing collar128. This allows the slip segments 120 to pass about a casing collar 128of the casing string 126 as the slip bowl assembly 102 is run into thewellhead housing 130 via the running tool 100. With the slip segments120 held by the outer sleeve 110 in this manner, the slip bowl assembly102 can be run into the wellhead housing 130 over the collar 128 andlanded on a landing shoulder 132 of the housing 130. Consequently, theslip bowl assembly 102 can be run into the wellhead housing 130 over thecollar 128 and be used to suspend the casing 126 without first cuttingthe casing 126 below the collar 128. While the shear pins 112 are shownin FIG. 3 holding the slip segments 120 to the outer sleeve 110, it willbe appreciated that shear pins 112 could also or instead be used to holdthe slip segments 120 to some other component, such as to the slip bowl116, during installation. Further, in at least some embodiments, ratherthan removing the BOP 11, the slip bowl assembly 102 can be run into thewellhead housing 130 with the running tool 100 through the BOP 11.

Once landed within the wellhead housing 130, the slip segments 120 canbe moved to a setting position so as to engage and grip the casing 126,as generally shown in FIG. 4. More specifically, after landing the slipbowl assembly 102 on the landing shoulder 132, a downward force isapplied to the slip segments 120 by the running tool 100 (via pipe 104and inner sleeve 106) such that the inner sleeve 106 moves downward withrespect to the outer sleeve 110, pushes the slip segments 120, andshears each of the shear pins 112 into two pieces—namely, a shear pinportion 112A that remains with the outer sleeve 110 and a shear pinportion 112B that remains with the slip segment 120. Once the shear pins112 are sheared and the slip segments 120 are released from the outersleeve 110, the slip segments 120 (which remain affixed to the slip bowl116 via holding pins 122) move into the setting position with slip teeth123 against the casing 126.

The holding pins 122 and elongated slots 124 cooperate to maintaincircumferential alignment of the slip segments 120 while allowing theslip segments 120 to slide downward and radially inward until theycontact the casing 126. The slip segments 120 may slide downward intocontact with the casing 126 under the force of gravity. Further, thepins 108 and grooves 109 enable relative axial movement of the innersleeve 106 with respect to the outer sleeve 110, and in at least someembodiments the inner sleeve 106 is pushed downward with respect to theouter sleeve 110 to drive the slip segments 120 into the settingposition. It will be appreciated that in this setting position the areagenerally circumscribed by the slip segments 120 (i.e., the outerdiameter of the casing 126) is smaller than the outer diameter of thecasing collar 128.

Once the slip segments 120 move into the setting position against thecasing 126, the casing 126 can be pulled upward to tension the casing toa desired hanging weight. This upward force may then be reduced to causethe slip segments 120 to tightly grip the casing 126 so that the casing126 is held in tension and suspended within the well 14 via the slipsegments 120. Following setting of the slip segments 120, the runningtool 100 can be removed, as shown in FIG. 5 and described above.

FIG. 6 is a flowchart representing a method of installing the slip bowlassembly 102 in a wellhead housing 130 in accordance with oneembodiment. The method represented in FIG. 6 starts at 136 withconnecting the slip bowl assembly 102 to the running tool 100. In atleast some embodiments, this includes inserting the retainer screws 114of the running tool 100 into retaining slots 118 of the slip bowlassembly 102, as described above. Connecting the running tool 100 andthe slip bowl assembly 102 together also includes retaining the slipsegments 120 in a retracted running position, such as by fastening theslip segments 120 to the outer sleeve 110 with shear pins 112 to holdthe slip segments 120 away from the center of the slip bowl assembly102.

The method continues at 138 with running the slip bowl assembly 102 withthe running tool 100 through one or more BOPs 11 and landing the slipbowl assembly 102 on a landing shoulder 24 (e.g., shoulder 132) in awellhead housing (at 140). While BOPs 11 remain installed on thewellhead during running of the slip bowl assembly 102 in some instances,in other embodiments the BOPs 11 are removed and the slip bowl assembly102 is run into the wellhead without passing through the BOPs 11. At142, the method continues with applying force on the running tool 100from above, which forces the inner sleeve 106 downward with respect tothe outer sleeve 110 (e.g., with pins 108 moving downward within thegrooves 109), thereby shearing the shear pins 112. At 144, downwardmovement of the inner sleeve 106 or gravity causes the slip segments 120to slide down from the running position to the setting position incontact with the casing 126. In at least some instances, the methodcontinues (at 146) with putting tension on the casing 126 to a desiredhanging weight to facilitate gripping of the casing with the slipsegments 120. At 148, the method concludes with removing the runningtool 100, such as by rotating the running tool 100 to disengage theretainer screws 114 from the retaining slots 118 and then lifting therunning tool 100 out of the wellhead through the one or more BOPs 11.

While the aspects of the present disclosure may be susceptible tovarious modifications and alternative forms, specific embodiments havebeen shown by way of example in the drawings and have been described indetail herein. But it should be understood that the invention is notintended to be limited to the particular forms disclosed. Rather, theinvention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the invention as defined by thefollowing appended claims.

1. A system comprising: a slip bowl assembly comprising a slip bowl anda plurality of slip segments, wherein each of the plurality of slipsegments is movably affixed to the slip bowl for movement between asetting position and a running position; and a running tool comprisingan inner sleeve positioned within an outer sleeve, wherein the outersleeve is configured to hold the plurality of slip segments in therunning position to facilitate installation of the slip bowl assemblyand the inner sleeve is configured to move with respect to the outersleeve so as to cause the plurality of slip segments to move from therunning position to the setting position.
 2. The system according toclaim 1, wherein the outer sleeve holds the plurality of slip segmentsin the running position with shear pins.
 3. The system according toclaim 2, wherein the inner and outer sleeves are arranged such that theshear pins can be sheared via movement of the inner sleeve with respectto the outer sleeve to allow the plurality of slip segments to move fromthe running position to the setting position.
 4. The system according toclaim 1, comprising a retention pin that retains the outer sleeve to theinner sleeve.
 5. The system according to claim 4, wherein the retentionpin is positioned in the inner sleeve and extends radially outward intoan interior groove of the outer sleeve.
 6. The system according to claim5, wherein the outer sleeve hangs from the retention pin and theinterior groove and the retention pin cooperate to allow relative axialmovement of the inner sleeve with respect to the outer sleeve.
 7. Thesystem according to claim 1, wherein the slip bowl comprises a pluralityof elongated slots and the plurality of slip segments are movablyaffixed to the slip bowl via holding pins extending into the pluralityof elongated slots.
 8. The system according to claim 1, wherein theouter sleeve is coupled to the slip bowl assembly by a retainer fastenerextending axially from the outer sleeve and received in a slot of theslip bowl.
 9. The system according to claim 1, wherein the slip bowlincludes a conical inner surface that biases the slip segments into thesetting position.
 10. A system comprising: a slip bowl; a running toolcoupled to the slip bowl; and slip segments fastened in a runningposition to the running tool, wherein the running tool is configured torelease the slip segments from the running position and cause the slipsegments to move with respect to the slip bowl into a setting positionagainst a pipe.
 11. The system of claim 10, wherein the slip segmentsare fastened to the running tool with shear pins.
 12. The system ofclaim 11, wherein the running tool includes an inner sleeve and an outersleeve, the slip segments are fastened to the outer sleeve with theshear pins, and the inner sleeve is moveable with respect to the outersleeve to allow the inner sleeve to cause the shear pins to shear andthe slip segments to move from the running position to the settingposition.
 13. The system according to claim 10, wherein the slipsegments are movably fastened to the slip bowl.
 14. A method comprising:providing a slip bowl assembly comprising: slip segments movably affixedto a slip bowl; a running tool including an inner sleeve and an outersleeve; and shear pins holding the slip segments in a first position;running the slip bowl assembly, via the running tool, along a casingstring with the slip segments in the first position; and shearing theshear pins after running the slip bowl assembly along the casing stringsuch that the slip segments move with respect to the slip bowl from thefirst position to a second position in which the slip segments contactthe casing string.
 15. The method according to claim 14, comprisinginserting retainer fasteners extending axially from the outer sleeveinto mating slots of the slip bowl assembly to couple the slip bowlassembly to the running tool.
 16. The method according to claim 14,wherein running the slip bowl assembly along the casing string includesrunning the slip bowl assembly past a casing collar of the casingstring.
 17. The method according to claim 14, wherein running the slipbowl assembly along the casing string includes running the slip bowlassembly through a blowout preventer.
 18. The method according to claim14, wherein running the slip bowl assembly along the casing stringincludes running the slip bowl into a wellhead housing and landing theslip bowl assembly on a shoulder within the wellhead housing.
 19. Themethod according to claim 18, further comprising disconnecting therunning tool from the slip bowl assembly and removing the running toolfrom the wellhead housing.
 20. The method according to claim 14, whereinthe shear pins fasten the slip segments to the outer sleeve and shearingthe shear pins includes axially moving the inner sleeve with respect tothe outer sleeve to push the slip segments and shear the shear pinsfastening the slip segments to the outer sleeve.